Transposable elements(TEs) are fragments of DNA that can “jump” in the chromosomes of eukargotes. TEs are classified into two different groups according to their mode of transposition: DNA transposable elements and retrotransposable elements. Recently, two novel families of TEs were discovered by comprehensive analysis of genomic sequences, called MITEs and Helitrons. Customarily, TEs are activated by stress conditions, but many TEs are active to transpose under normal growth conditions. The amplification and the removal of TEs contribute to the genome size variability of plants. TEs can increase the diversity of transposons, create new genes by causing removing, amplifying, unequally cross-over, capturing DNA fragments, or by exon shuffling. TEs scattering within the genome could be the source of the variation required for gene evolution.